1. Field of the Invention
The present invention relates to a medical prosthesis for human implantation, and in particular, to a surgical patch that is used for repairing tissues or organs during surgery.
2. Description of the Prior Art
Repair of defective tissues and organs is often required in modern surgical techniques, for example, repair of dura mater, repair of defective pleura, repair of peritoneum, repair of hernial strain, repair of diaphragm, repair of blood vessels, repair of atrial septum, repair of pericardium, repair of kidneys, etc. There are many “surgical sticking patches” that are currently being provided to meet clinical demands. However, these products were first prepared with synthetic materials.
These synthetic materials utilized in preparing the surgical sticking patches include polypropylene, polyethylene, polyamide, Dacron resin, polytetrafluoroethylene, silicone gel, and carbon fiber, among others, which are foreign to the human body and that remain permanently in the repaired tissues. These materials often lead to non-bacterial inflammatory diseases due to physical irritation and complications caused by chronic rejective reaction.
Other patches have been prepared with absorbable synthetic materials such as polyglycolic acid (PGA), polylactic acid (PLA) and copolymer thereof (PGA-PLA). However, the rate of degradation of these materials is difficult to control to coincide with the rate of tissue recovery, so the efficacy is often uncertain due to rapid degradation. In addition, the degraded products can bring local acidity which affects normal healing of the repaired tissues.
Animal membrane tissues such as fascia and bovine pericardium have also been utilized in recent years through conventional processes including defatting, cell removal and fixation with glutaraldehyde, but elimination of antigens is hardly effective because cell removal is employed as the only means for eliminating antigens. Additionally, fixation of tissues with glutaraldehyde is achieved by crosslinking through acetalization, and glutaraldehyde is released during degradation, leaving residual toxicity and causing more potent cellular toxicity so that its growth in the inherent tissue becomes difficult, resulting in poor repair effect.